| Message ID | 1336698442-25148-1-git-send-email-bpoirier@suse.de |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Benjamin Poirier <bpoirier@suse.de> Date: Thu, 10 May 2012 21:07:22 -0400 > - return mtu - 2; > + return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) - > + l3_adj) & ~(align - 1)) + (l3_adj - 2); > } The formatting of this expression is completely wrong, you need to make the "l3_adj" in the second line be aligned with the openning parenthesis on the previous line at a depth determined based upon how deeply in the openning parenthesis context this expression sits. Just using TABS is ugly, and not allowed. Use something like emacs's "C mode" with Linux coding style enabled to assist you if you can't figure it out yourself. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 89a47b3..b2503f6 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -459,28 +459,22 @@ static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) struct esp_data *esp = x->data; u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4); u32 align = max_t(u32, blksize, esp->padlen); - u32 rem; - - mtu -= x->props.header_len + crypto_aead_authsize(esp->aead); - rem = mtu & (align - 1); - mtu &= ~(align - 1); + unsigned int l3_adj; switch (x->props.mode) { - case XFRM_MODE_TUNNEL: - break; - default: case XFRM_MODE_TRANSPORT: - /* The worst case */ - mtu -= blksize - 4; - mtu += min_t(u32, blksize - 4, rem); - break; case XFRM_MODE_BEET: - /* The worst case. */ - mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem); + l3_adj = sizeof(struct iphdr); break; + case XFRM_MODE_TUNNEL: + l3_adj = 0; + break; + default: + BUG(); } - return mtu - 2; + return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) - + l3_adj) & ~(align - 1)) + (l3_adj - 2); } static void esp4_err(struct sk_buff *skb, u32 info)
Corrects the function that determines the esp payload size. The calculations done in esp4_get_mtu lead to overlength frames in transport mode for certain mtu values and suboptimal frames for others. According to what is done, mainly in esp_output(), net_header_len aka sizeof(struct iphdr) must be taken into account before doing the alignment calculation. Signed-off-by: Benjamin Poirier <bpoirier@suse.de> --- Changes since v1: * introduce l3_adj to preserve the same returned value as before for tunnel mode For example, with md5 AH and 3des ESP (transport mode): mtu = 1499 leads to FRAGFAILS mtu = 1500 the addition of padding in the esp header could be avoided Tested with * transport mode E * transport mode EA * transport mode E + ah * tunnel mode E Not tested with BEET, but it should be the same as transport mode draft-nikander-esp-beet-mode-03.txt Section 5.2: "The wire packet format is identical to the ESP transport mode" --- net/ipv4/esp4.c | 24 +++++++++--------------- 1 files changed, 9 insertions(+), 15 deletions(-)